Oblique Digital Image Gallery

Pinworm (Enterobius vermicularis)

Pinworms, as their common name implies, are tiny pin-shaped nematodes known as Enterobius vermicularis to the medical and zoology communities. Also called seatworms or threadworms, the small, whitish roundworms are responsible for contagious intestinal parasite infestations that commonly inflict preschool children and other crowded settings such as nurseries, schools, and hospitals.

Although adult pinworms inhabit the large intestine, the eggs are laid outside of the anus during the night, creating a severe itching sensation. Other symptoms include disturbed sleep, decreased appetite and weight loss. Spread from person to person usually occurs with contaminated clothing, bedding, toys, and dirty hands, but the eggs can also drift through the air where they are inhaled or swallowed. Once they enter the new host, the eggs hatch in the small intestine and travel down to the large intestine for maturation.

Prevention measures, primarily through good personal hygiene with emphasis on hand washing after using the bathroom, are much more valuable than pharmaceutical treatment of outbreaks. Washing towels, bedding, and clothes in hot water and a mild bleach solution helps stem an infestation before it becomes widespread. Worm-killing medicines such as pyrantel pamoate, mebendazole, and piperazine are often prescribed, although there is some controversy in the medical community of even treating the condition.